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Approach to dizziness
From the podcasts on 'Vertigo' and 'Dizziness' 4 questions 1. Is it syncope or vertigo? Sensation of near-faint or syncope: related to transient but diffuse cerebral hypoxia Vertigo: related to abnormalities in peripheral or central vestibular system : o illusion of movement, usually rotatory, but can be a feeling of linear displacement or tilt 2. If vertigo, is it peripheral or central? Peripheral (inner ear and VIII nerve) or central (brainstem and cerebellum) in origin Peripheral - absence of CNS symptoms/ signs - nystagmus - head thrust sign - nausea and vomiting are usually severe - may be associated with deafness, tinnitus or fullness of ear Peripheral nystagmus - Unidirectional - Fast phase away from site of pathology - Mixed horizontal and rotatory - Worse on looking away from site of pathology Central ''' - Symptoms and signs of dysfunction of cranial nerves 3, 7, 9, 10, 12 - Weakness, incoordination , numbness of limbs - If balance is so severely affected as to prevent standing or walking, consider a central lesion - Nystagmus Central nystagmus - Changes direction with gaze: fast component to direction of gaze - Rotatory - Vertical 3. What is the duration? BPPV: few minutes Vestibular neuronitis/labrynthitis: 1 to 2 days Posterior ciculation TIA: variable Posterior circulation stroke: on-going Migraine: hours Meneiere’s: hours Labyrinthe fistulae: variable 4. Is this the first episode? '''First episode Posterior circulation stroke Vestibular neuronitis/ labrynthitis First presentation of any of the causes of recurrent vertigo Recurrent 1. Benign Paroxysmal Positional Vertigo (BPPV): pure vertigo that lasts seconds to minutes, associated with looking up or lying back Possible misleads in history to underdiagnosis: - non-specific sensation of motion sickness that can last for many hours after an attack of BPPV - tendency to get repeated attacks over a period of days as vertigo lasting several days Do Dix Hallpike manoeuvre: Patient is brought from sitting to supine position, with the head turned 45 degrees to one side and extended about 20 degrees backward. A positive testwill have rotatory nystagmus, with the fast phase toward the affected ear. (Direction of fast phase is defined by rotation of top of the eye, either clockwise or counter-clockwise. Can be made more sensitive by making patient wear Frenzel goggles. Key characteristics of positive test *Vertigo *Latency of onset (usually 5-10 seconds) *Torsional (rotational) nystagmus. If no torsional nystagmus occurs but there is upbeating or downbeating nystagmus, a CNS dysfunction is indicated. *Fatiguability or habituation of nystagmus on repetition. Multiple repetition of the test will result in less and less nystagmus. *Reversal. Upon sitting after a positive maneuver the direction of nystagmus should reverse for a brief period of time. Epley’s maneuver for canalith repositioning in BPPV For right BPPV, when nystagmus detected on right side with neck extended, have the patient remain in that position for 1 min. Turn head to left side, neck still extended, wait 1 min. Roll onto left side with face down, wait 1 min. Sit up keeping face turned downward, wait 1 min. Remember that not all positional vertigo or nystagmus is BPPV. If there is no latency, fatiguability or habituation of nystagmus on the Dix-Hallpike test, consider posterior fossa lesions. 2. Posterior circulation TIA Stereotypic vertigo without any other signs of CNS dysfunction and lasting more than 3 to 6 months is usually not TIA of the posterior circulation. 3. Migraine Common cause of vertigo in young Consider migraine as a cause of recurrent vertigo when other causes have been ruled out, and in young/ middle aged patients with otherwise typical migraine. 4. Meniere’s syndrome Recurrent vertigo that lasts minutes and associated with nausea, vomiting, aural fullness, roaring tinnitus and hearing loss is often Meniere’s syndrome 5. Labyrinthine fistulae Syncope Due to transient cerebral hypoxemia/ hypoperfusion Causes (mechanistic approach) Cardiac - arrhythmia - outflow obstruction: AS, HOCM Blood pressure - postural hypotension : o hypovolemia : o drugs : o autonomic neuropathy Blood ''' - anemia, polycythemia - general medical causes eg. hypoglycemia, hyponatremia '''Blood vessels - vertebrobasilar stroke/ TIA Nerve to blood vessels: neurogenic - vasovagal syncope : o constitutional predisposed : o typical precipitating factors : o premonition : o very transient loss of consciousness that resolves on lying supine